Hashimoto thyroiditis is an autoimmune disease that attacks the thyroid tissue through an immune process, often intermittently. The disease first appears with the gradual enlargement of the thyroid gland and slow progression of hypothyroidism due to the infiltration of immune cells into the thyroid tissue, causing its destruction.

Hashimoto thyroiditis is the most common endocrine disorder and cause of hypothyroidism in the Western world. The disease affects five to ten times more women, than men, depending on your country of residence.

Environmental and genetic factors both play essential roles in developing Hashimoto thyroiditis. Of the environmental factors, diet, stress, smoking, and alcohol consumption are the most crucial. [1]

In Hashimoto thyroiditis, the thyroid gland loses its ability to store iodine. Thus it fails to respond to thyroid-stimulating hormone (TSH) to produce the thyroid hormone thyroxine (T4), which is partially made with iodine. T4 leads to the production of triiodothyronine (T3). Both are required to regulate the body’s metabolism, heart rate, digestion, and growth.

Muscle pain, chest pain, stiffness, and rheumatoid arthritis, occur in ¼ of people suffering from Hashimoto thyroiditis.

Hashimoto thyroiditis is often associated with type 1 diabetes and other autoimmune disorders such as celiac disease. [2] 

Also, hypothyroidism, thyroid inflammation, and hyperthyroidism make people more susceptible to autoimmune disease. [3]

If the swelling of the neck as a result of the growth of the thyroid gland due to Hashimoto thyroiditis becomes a problem because of the pressure it places or how it looks, thyroid hormone supplementation is advisable. The standard treatment involves daily supplementation with the hormone L-thyroxine or levothyroxine. It is crucial to supplement properly since excess supplementation will have dangerous side effects of hyperthyroidism, leading to heart arrhythmias, especially atrial fibrillation, and osteoporosis leading to fractures. [4]

Supplementation with thyroid hormone causes a gradual reduction in the size of the thyroid gland back to its average size after a few weeks to months of treatment. The treatment is more receptive and quicker among younger people. [5-6]

However, there is no proof that thyroid hormone supplementation stops the ongoing thyroid inflammation (thyroiditis), but antibody levels have been shown to fall after several years of therapy. [7]

Diet

Unfortunately, no scientific societies have made dietary recommendations for people with Hashimoto thyroiditis. Yet, these are highly needed due to the role of thyroid hormones in the regulation of metabolism and the effects of diet on inflammation. 

The resting metabolic rate in people with Hashimoto thyroiditis decreases with decreasing thyroid function; therefore, body weight is often increased. [8] 

Due to the significance of thyroid hormones for metabolism, thyroid hormone supplementation is usually the first line of treatment. 

But diet can undoubtedly support the process by reducing inflammation, oxidative stress, and contaminants from animal products and processed food, preventing fluctuating blood sugar levels, unstable immune function, and obesity. [9-11]. 

Let’s look into dietary and lifestyle recommendations:

Fiber

Hypothyroidism itself may cause disorders with digestion, leading to constipation; therefore, adequate water and a minimum of 25 g of dietary fiber are recommended daily. [12]

Fiber intake is also crucial for a healthy microbiome, and the microbiome is vital for immune health. The state of the microbiome constantly adapts to eating habits. Many people with Hashimoto’s have an unhealthy microbiome due to faulty eating habits that stimulate autoimmune processes. [13-14] 

Fluctuating thyroid hormone levels may also affect the microbiome’s composition, leading to an increased risk for SIBO (small intestine bacterial overgrowth). Changes in the microbiome often lead to changes in metabolism, and changes in metabolism lead to changes in the microbiome because the microbiome depends on thyroid hormones and thyroid function. 

Synthetic sweeteners also affect the microbiome and increase intestinal permeability in people with Hashimoto thyroiditis. [15-18]

To improve the quality of your microbiome, you should reduce processed foods to a minimum and regularly consume fruits, vegetables, whole grains, and legumes at least twice a day. You can lower your intake of saturated fats and increase omega-3 fatty acids by consuming walnuts and chia, and flaxseeds regularly.

Limit Meat and Dairy Consumption 

Increased animal fat and processed meat consumption in people with Hashimoto thyroiditis lead to the progression of the disease. Dairy products containing lactose should also be avoided, especially if taking levothyroxine since lactose intolerance reduces the bioavailability of levothyroxine and may require higher doses. Lactose intolerance is found in 75.9% of people with Hashimoto thyroiditis. [19-20]. 

Follow a Plant-Based Diet

Fruits and vegetables reduce the oxidative damage caused by free radicals produced in the thyroid gland. A plant-based diet is full of many nutrients, including iron, calcium, zinc, manganese, selenium, B vitamins, and magnesium, all necessary for the proper functioning of the immune system and thyroid gland. 

A plant-based diet (such as the Guerrilla Diet) is associated with a lower risk of Hashimoto thyroiditis and a decrease in weight. There is a therapeutic significance of weight loss for Hashimoto thyroiditis. [21] 

I recommend consuming carbohydrates from whole grains as these have a higher nutritional density and more dietary fiber. Increasing fiber intake supports a healthy microbiome that, among the other mentioned benefits, also prevents unhealthy bowel function, a common problem in hypothyroidism. Plant-based foods, including fruits, vegetables, whole grains, and legumes, are excellent sources of fiber supporting a healthy microbiome, especially when also removing simple sugars and processed foods. 

My book, The Guerrilla Diet and Lifestyle Program will help you incorporate a healthy balanced whole food, plant-based diet that supports a healthy microbiome and will help you lose any excess weight healthily.

Avoidance of Gluten

Due to cross-reactions between gluten and thyroid antigens, gluten is associated with autoimmune diseases, including Hashimoto thyroiditis. There is also often coexistence of other autoimmune diseases like celiac disease, gastritis, and gluten intolerance in people with Hashimoto thyroiditis. [22-24]. Testing for celiac disease should be carried out if you have a Hashimoto thyroiditis diagnosis.  

One pilot study suggests the beneficial effect of a gluten-free diet for Hashimoto thyroiditis. This study found a significant reduction in antibodies directed to thyroid peroxidase (Anti-TPO) and thyroglobulin (Anti-TG). Thyroid secretory functions also improved. [25]

Although there are no recommendations for gluten elimination in Hashimoto’s diet therapy, I recommend a gluten-free diet for people with Hashimoto thyroiditis, but only if there is coexistence with gastritis or celiac disease. Because a gluten-free diet may be harmful due to many possible nutrient deficiencies and increased heart disease risk if done improperly. [26]

Other allergies that exist are also associated with Hashimoto thyroiditis. Therefore, eliminating food allergens from the diet is essential if a true allergy exists.

Iodine 

Iodine intake influences the incidence of Hashimoto’s thyroiditis and hypothyroidism. 

Chronic exposure to excess iodine intake leads to the disease, partly because the high levels of iodine in the thyroid gland produce a more robust immune response. [27] For this reason, I do not recommend iodized salts and instead recommend consuming seaweed once a week if you are vegan. 

Selenium 

Selenium is essential to thyroid function. The thyroid gland has the most selenium in it among all tissues. [28-29]

Thyroid peroxidase is the enzyme produced by the thyroid gland that, with iodine, creates the hormones T3 and T4. Also, the potent antioxidant glutathione peroxidase enzymes all have selenium and cysteine in them. They are essential for thyroid function since they protect the thyroid gland from excessive hydrogen peroxide produced during the insertion of iodine when thyroid hormones are produced.

A low selenium intake of below 40 mcg a day is a risk factor for Hashimoto thyroiditis development. [30]

In one randomized controlled prospective study, 77 pregnant women with the presence of thyroid peroxidase antibodies in their blood (suggesting that the cause of thyroid disease is an autoimmune disorder) received 200 mcg of selenomethionine daily starting at the 12th week of pregnancy, and 74 women with the same antibody levels received a placebo. The treated group had significantly lower thyroid peroxidase antibodies at the end of pregnancy and after childbirth while on treatment. This reduced the incidence of permanent hypothyroidism. [31] 

Another study showed that 200 mcg selenium in the form of l-selenomethionine orally for six months caused a significant decrease of 21% in thyroid peroxidase antibody levels. Cessation of the supplement caused an increase in the thyroid peroxidase antibody concentrations. [32] 

A systematic review and meta-analysis revealed that selenium supplementation reduced thyroid peroxidase antibodies after 3, 6, and 12 months in people with Hashimoto’s and after three months in an untreated population [33]

A combined treatment with myo-inositol and selenomethionine supplementation was reported to have even more beneficial results. [34] This combination was also shown to decrease TSH, thyroid peroxidase antibodies, and thyroglobulin antibody levels and enhances personal well-being, restoring normal thyroid function in people with Hashimoto thyroiditis. [35]

Inadequate selenium intake increases thyroid size. [36-37]

Sufficient selenium intake is vital in areas of population iodine deficiency and excess. In areas of low selenium intake, a supplement of 50-200 mcg per day of selenomethionine may be appropriate.

Selenium-rich foods include Brazil nuts, green peas, beans, broccoli, and potatoes. 

However, it is crucial to check selenium levels before supplementing because you may reach toxic levels when there is excess dietary intake or soil contamination in certain places worldwide. [38-40] 

Iron

Iron status should be checked in all people with Hashimoto thyroiditis, especially menstruating women, since iron deficiency impairs thyroid function. Although anemia does not result from Hashimoto thyroiditis, it is often present. 

People with Hashimoto thyroiditis are often deficient in iron since coexisting autoimmune gastritis, and celiac disease impairs iron absorption. [41] 

Thyroid peroxidase, the enzyme responsible for producing thyroid hormones, contains iron and becomes active only after binding to iron. Iron deficiency blocks the activity of thyroid peroxidase.

As a result, a reduction in the production of thyroid hormones is found, as is an increase in thyroid-stimulating hormone levels and thyroid gland size.

Supplementation of anemic women with impaired thyroid function with iron improves thyroid-hormone levels and the functioning of the thyroid gland. [42] You may supplement with iron bisglycinate to prevent digestive issues.

Iron is found in cocoa and bitter chocolate, green leafy vegetables, quinoa, sesame, chia, flax, hemp, and pumpkin seeds, all legumes, cashew nuts, dried figs, apricots, and raisins.

Vitamin D

Lower vitamin D status has been found in people with Hashimoto thyroiditis [43]. An inverse relationship between vitamin D levels and thyroid peroxidase antibodies has been found, especially vitamin D levels below 30 ng/ml.

I suggest supplementing with 1000-2000 IU of vitamin D daily during winter.

Zinc

Zinc levels are lower in all people with autoimmune diseases, including Hashimoto thyroiditis [44]. One study involving 201 people found a significant correlation between lower blood zinc levels with increased thyroid size and thyroid autoantibodies. [45]. You may supplement with 15-20 mg zinc thrice a week. 

Stop Smoking and Drinking Alcohol

Smoking and drinking highly increase oxidative stress, leading to the progression of Hashimoto’s disease. [46-48]

Although consuming fruit and vegetables reduces the amount of oxidative damage caused by oxidative stress, it is still best to reduce free radical damage by ingesting fewer toxins. 

Feel free to comment below and let me know what you liked best about this article.

Thank you for taking the time to read this. I’d be honored if you would share it with your family, friends, and followers by clicking the Like, Tweet, and Share buttons. If you are serious about improving your health no matter what your age or circumstances, and are ready to finally achieve optimal health and lose the weight you’ve been struggling with, then click HERE to check out my online Guerrilla Diet Wholistic Lifestyle Bootcamp for Healthy and Lasting Weight Loss.

If you are not already on my mailing list where you will receive my weekly articles packed with scientifically based health, and nutrition content, as well as many FREE bonuses and special offers, and much more, then click HEREto subscribe.

Thank You, 🙂

Dr. Galit Goldfarb

References